Roasting furnace



July 16, 1929. N, T, WELLMAN 1,721,265

ROASTING FURNACEA Filed June 25, 1925 3 Sheets-Sheet l FLUU? LINE Forum, HEART N` T. WELLMAN ROASTING FURNACE Filed June 25, 1925 3 Sheets-Sheet 2 FLUUF LINE A Ifo/Mrs July 16. 1929. N .-r, WELLMAN 1,721,265

RGASTING FURNGE Filed June 25, 1925 5 Sheets-Sheet 3 A TTORNE VS Patented July 15, 1929.v

UNITED NOL T. WLLMAN, OF RIDLEY PARK, PENNSYLVANIA, ASSIGNOR' TO GENERAL CHEMICAL COMPANY, F YORK, N. Y., A CORPORATION OF NEW YORK.

ROASTING FURNACE.

Application filed June 25, 1925. Serial No. 39,436.

My invention relates to furnaces in which a gaseous mixture containing sulfur dioxide is produced by the roasting of pyrites or the like. In some cases. it is desirable to enrich the raw material as regards 'the sulphur contents, by supplying an additional amount of sulfur or brimestone. The object of my invention is to provide a simple and positively operating device for feeding such supplementary sulfur to the furnace in a definite relation to the amount of ore supplied and under such conditiors as to prevent the entrance of air into the furnace at the point where the sulfur is admitted.

I will now describe, as a typical example of my invention, its application to a roasting furnace of the well known Herresholi' design. Such an installation is illustrated by the accompanying drawings in which Fig. 1 is a side elevation of the furnace, with parts in section; Fig. 2 is a front elevation; Fig. 3 is a plan View; Fig. 4 is a detail plan view of the devices controlling the supply of ore and sulfur respectively; Fig. 5 is a plan view of a melting pan, with parts in section, on line 5 5 of Fig. 7;.Fig. 6 is an elevation looking in the direction of the arrow 6 in Figs. 5 and 7, and Fig. 7 is a vertical section on line 7-7 of Fig. 6.

At 10 I have indicated the hopper for feeding t-he ore to the furnace, said hopper having an outlet controlled by a gate 11 which rotates about a vertical axis 12. The 'ore then passes in the usual way to the uppcrmost of the super-posed hearths 13 of the Herreshott1 furnace 14, and` then to the, 'hearths below. in any well known or approved manner. The mechanism for operating the gate 11 may be the usual one and has not been shown in its entirety.

The bri-nistone or sulfur is stored in a bin 15 having a bottom outlet controlled by an oscillating knife gate 16 connected operatively with the ore-feeding gate I11, for instance by means of a horizontal rocking arm 17 fulc'rumed at 18 and actuated by means of an upright rod 19 working in a Slot 17 of said arm and attached to the gate 11 or a member moving in' unison therewith. The gate 16 sweeps the sulfur off a table 20 into a chute 20. Thus sulfur will be fed only when ore is being fed, and the proportion of these two materials will be kept constant. From the hopper or bin l15 the sulfur passes through successive pipes 21, 22, 23, to a meltform a body of liquid into which'dips the lowerend of the feed pipe 23. A liquid seal is thus obtained, and moreover the pan 24 seals the door 25 ofthe hearth, preventing the ent-rance of air at this point. y It will be understood that as the sulfur -melts in the pan 24. it will not pass on to the hearth until there is suliicient liquid or molten sulfur to seal the lower end of the feed pipe 23 and to reach the. level of the overflow located at the inner portion of the pan. The drawing indicates the well Vknown arrangement of openings or passages 13', 13 alternately at the central and tie marginal portions of successive hearths 13. and preferably the sulfur is fed to one of those hearths l(such as the fourth) which have the material-transferring passage at the outer portionl It will be understood that lthe material is fed inwardly on the odd-numbered hea'rths, and outwardly on the even-numbered hearths, by devices (rabble arms) 26, well known in connection with Herreshoii' roasting furnaces. The rabble arms are carried by the central rotary shaft 27 to which the gatell is Secured rigidly. The sulfur burned upon the (fourth) hearth increases the strength or SO, content of the gas delivered from the furnace.

Various modifications may be made without departing from the nature of my invention as set forth in the claims.

I claim:

1. A. roasting furnace having superposed hearths adapted to receive the material successively, a device for feeding ore to the uppermost hearth, and another feed device in operative connectionwith said ore-feeding device for supplying sulfur to one of the lower hearths.

2. A roasting furnace provided. with a device for feeding ore thereto, another feed device for supplying sulfur to said furnace, means for preventing air from being drawn into the. furnace through said last named feed device'and controlling devices for controlling respectively the feed of the ore and the sulfur, said devices being operatively connected for regulating proportionately the amounts of ore and of sulfur supplied by the respective feed devices.

3. A roasting furnace having superposed -hearths adapted to receive the'material successively, a device for feeding ore to the uppermost hearth, another feed device for supplying sulfur to one of the lower hearths means for preventing air from being drawn into the furnace through said last. named feed device, and controlling devices for controlling respectively the feed of the ore and 'the'sulfun said devices being operatively connected for regulating proportionately the amounts of ore and of sulfur supplied by .the respective feed devices.

with said ore-feeding device for supplying sulfur to a lower hearth having openings at its marginal portion.

5. A roasting furnace provided with a device for feeding ore thereto, a melting pan set in an opening of said furnace, and sealing said opening, and a device for feeding sulfur to said melting pan, to discharge molten sulfur therefrom into the furnace.

6. A roasting furnace provided with a device for feeding ore thereto, a melting pan set in l.1n/opening of said furnace, and sealing said opening, said pan having an overflow located at a the bottom of the pan and discharging into the furnace, and a device for. feeding sulfur to said melting pan, said sulfur-feeding device terminating within the melting pan, below the level of its overflow.

In testimony whereof I have hereunto set my hand.

NOEL T. WELLMAN.

substantial distance above 

